Welded exhaust bracket back on and fitted a new bit of hose for the rear heater, cut the crusty bit out and used some hose to replace it.
Cleaned the chassis with a wire wheel at the back (round where the spare goes), the bits of rust soon went back to clean metal, gave it a coat of rust converter to sort any little bits and splashed a bit of paint on. It's gonna take a good few hours to do the full chassis etc but will be worth it.
Considered making a new storage unit for the boot and selling the one I made for my last truck. I plan on putting the spare in the boot on top of the unit, laid it out in the boot and with a bit of tweaking will use it in the 80. Will leave enough space for the high lift and air compressor. It has an opening lid so will mean removing the spare when need to get in though so will see how it goes.